Viso's signing comes in a joint effort between the Andretti-led organization and the Venezuelan's former team, HVM Racing.
"I could not ask for more than to get the opportunity to drive for a championship team while representing my country," said Viso. "After five years in the series I believe I have found the right environment and look forward to having Ryan, James and Marco as teammates. I'm very proud to be able to move into the 2013 season with this new relationship; it's a dream come true."
The 27-year-old will run the #5 Team Venezuela PDVSA entry alongside returning pilots Ryan Hunter-Reay, Marco Andretti and James Hinchcliffe.
Rahal Letteran Lanigan Racing announced earlier this week that James Jakes will be joining the team full-time running the #30 Acorn Stairlifts sponsored entry.
“I wanted to put myself in a position where I could get results that I believe I am capable of and Rahal Letterman Lanigan Racing is a good fit for me,” said James Jakes. “If you look back at the results and the product that Bobby and the team have put on the track, he’s always got a car that is running up front and the team does things first class. I had negotiated with Bobby when I first came to the series but we weren’t able to put a program together until now. It will be great for the team to have two full-season cars to move ourselves forward and push us to where Bobby and the team want us to be – at the top of the grid.”
Rahal Letterman Lanigan has inquired INDYCAR about available numbers and will renumber Mike Conway's previously announced #30 Long Beach entry.